Process of making molded conductors.



carbon UNITED STATES PATENT OFFICE.

SAMUEL TROOD, OF WILKINSBURG. PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

PROCESS OF MAKING MOLDED CONDUCTORS.

No Ill-owing.

tors "and" it has specialreference to currentcarrymg conductors such .as may be employed as current collectors for dynamoelectric machines My invention has for one of its objects to provide a conductor which possesses the lubridating'qualities of agraphite brush but which is more durable and is a better conductor.

Another object of my invention is to pro vide a process by means of which a conduc- .tor having the properties above noted may be easily and economically constructed. As is well known, carbon brushes are employed as 'current collectorsof dynamd 1 electric machines to avoidthe sparking and wear of the commutator which occur whenv When a heavy metallic brushes are, used; load'is placed upon .themachine, alayer of deposited upon the commutator which interferes with the eflicient operation i of the machine.

According to the present invention, a conductor is provided in which is combined the conductin properties and the, lubricating qualities of a carbon have provided a process for confgraphite, soapstone, or-ot er, lubricating rial of arefractory' nature, tq f -'m0geneons mass'in which thernmju iticles are incese' material, which avoidsthjef use ofa ooked adhesive. ,Whon an adhesive is employed,

the body of the brush is usually 'n'ot homo;

geneons and the resistance oiithe brush increased. I i In .carr'ym out inve of a metallic brush tion, a" one tity I Specification of Letters Patent. P t nt t 15 1915- Application filed October a, 1913. Serial No. 793.116.

the resultant mixture is slightly plastic."

The relative amountsoi amalgam and graphite may be varied within celtain limits to control the resistance of the finished product. For example; if a low-resistance brush is desired, approximately five parts of graphite are added to one hundred parts of amalgam, while, for a high-resistance brush approximately twenty-five parts of graphite are added tp one-hundred parts of amalgam. It is to be understood that these proportions may be varied-betweeh and be.

yond the limits stated, in ord'epi' to obtain a brush of any desired resistance. 'lhe homogeneous mixture above described is then placed ina suitable mold-audio he v3 pressure is applied. The-compression of t mixture removes a large 'ier'centage of the mercury, the amount varying with the pres sure. Substantially all of the remainder of the mercury is then expelled byheating the,

moldedAarirsh, while under pl'es's'l'l'reg'to a degree sufficient to vaporize '-@th The mercury vapor maybe col; suitable manner, if deslred, f

The remora'l of mercury m which reduces" ducf'tiiigiijproperties. In some cases, it may be desirable to produce a slightly porous structure; and this may be accdmplished by adjl'lstiiiglithe amount of pressure employed and thereby controlling the proportion. of mercur' be removed by. distillation; It has iieen found that. approximatelyf90.% of thelmei cury may be removed by presehre-ofimcom venient degree.

7 i The resultant product ifsgahard compact and homogeneous mass ha'vmgfa' o' 'ctivity much higher than carbonralid of finely divided metal, such asjcogperor'a' j suit-able alloy, which; agood e10 uctor,

manner; If copper thoroughly mixed, at or Such a quantity of graphite is with a la divided gy con ition I mixing lubricating material with said amalgam and then removing substantially all of the mercurj from the mixture.

2. The process which consists in eomhining mercury with copper to form an amalgam, mixing finely divided lubricating; material with said amalgam to form a homogeneous masF, and then expelling sub5tantially all of the mercury from said mixture.

3. The process which consists in combin- 111g mercury with finely divided metal to form an amalgam, mixing finely divided curhtm with said amalgam, and then removing substantially all. of the mert-ury from the mixture by applying heat-and pressure,

4. The process which consists in combininn mercury and finely divided copper to form an amalgam. mixing finely divided (ill'hOfl with said amalgam to form a homogeneous mixture, and then ren'ioving subetantially all of the mercury from said mixture by applying pressure and heat.

5. The process which consists in combining mercury with metal to form an amalgam, mixing carbon with said amalgam at:

ing particles of (-arlain with a iilm of copper amalgam and then removing substantially all of themeruury from said amalgam by applying heat and pressure.

In testimony whereof. I have hereunto S\ll).' ft'lll)(2(l my name tllls 22nd day of Sept. 1913.

SA MUICL 'lltOOD.

\Vitnesses:

B. B. l'llNI-LS. M. G. Mnaz. 

